Potholes are well known to those who travel paved roadways. Moreover, the unavoidable appearance of potholes in paved road surfaces is a continuous problem to those responsible for the maintenance of the nation's roadways. Potholes most commonly appear during the winter months and are caused by rapid changes in the temperature of the pavement which lead to the cracking of the road surfaces. The crack in the road surface then lends itself to the entry of water, which upon freezing results in the loss of hunks of pavement leaving potholes.
Potholes present a definite hazard. They frequently cause vehicles to swerve from their intended path when attempting to avoid them, and when a vehicle strikes a pothole, it may be deflected, causing the driver to lose control of his vehicle. Tire and automobile frame damage may be the costly result to car and truck owners when potholes are struck. Finally, the cost incurred by municipal, state or federal agencies in repairing potholes and maintaining a smooth road surface is significant. Considerable economic drain is imposed on the agencies responsible as a result of the costs they must pay in repairing potholes wherever paved roads are maintained. In fact, with the tightening of federal, state and local budgets, the coats for the prompt and permanent repair of potholes are becoming increasingly prohibitive.
The current methods for the permanent repair of potholes are expensive, time consuming and frequently result in traffic delays. In an attempt to minimize traffic delays and cost, most pothole repairs are temporary and involve no more than pouring a heated bituminous material into the pothole and compacting it down to a smooth surface.
One generally accepted method for the temporary filling of potholes comprises filling the pothole with an asphalt-concrete mix. The hole must be dried before the addition of the filler, and the asphalt-concrete mix subsequent to being applied to the pothole must be thoroughly compacted with either a pneumatic compactor, a vibratory plate compactor or a roller. This procedure is relatively expensive since it utilizes an expensive asphalt-concrete mixture which in turn requires expensive equipment to apply it. Moreover, there is a considerable amount of human labor associated with the repair of potholes by this method which further increases the cost of repair. In making a repair utilizing an asphalt-concrete filler a three-man crew is required--namely, a compactor operator, truck driver and a laborer to add the filler to the hole.
The prior art does not disclose a method of repairing potholes in road surfaces utilizing a relatively inexpensive material, which requires little or no preparation prior to use and requires a minimum of time and human labor to effectuate a road repair utilizing it.
The method of this invention employs a self-hardening mixture of fly ash and water to fill crevices or potholes in road surfaces. Fly ash is plentiful and cheap. In fact, fly ash is often viewed as an undesirable waste product resulting from the combustion of coal or other solid fossil fuels by electric utility plants.
In the past, attempts have been made to find commercial applications for fly ash. For example, fly ash has been used in the construction of highway embankments, roads, or as a component in concrete or asphalt formulations. In addition, fly ash has been utilized in the form of a grout to fill an abandoned sewer. See "Ash at Work--Process and Technical Data" NAA Summary Report (May-October 1975); Professional Engineer, pp. 18-22, July 1974; "How Fly Ash Improves Concrete Blocks, Ready-Mix Concrete, Concrete Pipe," Concrete Industries Year Book, pp. 1-6 (1970-1977). However, fly ash has not been utilized to fill potholes which result from the deterioration of conventional road surfaces comprised of, for example, asphalt, concrete, macadam or the like.
It is an object of this invention to provide a simple, quick and inexpensive method of filling potholes to restore a safe and long-lasting road surface.
It is a further object of this invention to provide a method of filling crevices in road surfaces employing a relatively inexpensive by-product material which, unlike conventional road fill materials, requires little or no preparation prior to use, and a minimum of human labor to effectuate road repairs utilizing it.